Two years ago, UE4 introduced support for third party HRTF spatialization. In 4.16, spatialization plugins can customize the behavior of HRTF processing on a per-source basis. Users configure spatialization plugins with Spatialization Plugin Settings assets. The Steam Audio plugin provides robust HRTF processing and lets users choose between nearest-neighbor and bilinear HRTF interpolation.

Direct-Sound Occlusion

UE4 provides a raycast occlusion solution by default. In 4.16, occlusion plugins can handle how direct sound is occluded on a per-source basis. Users control the processing with Occlusion Plugin Settings assets. The Steam Audio plugin lets users choose between raycast and partial occlusion, and whether to apply physics-based attenuation.

Physically-based Sound Propagation

UE4 allows users to author reverbs using traditional reverb volumes. In 4.16, reverb plugins can efficiently apply convolution reverb to mixed audio and customize how reverbs are generated and applied on a per-source basis. Users control the processing with Reverb Plugin Settings assets. The Steam Audio plugin lets users choose between realtime and baked sound propagation and configure a mixing fraction. Steam Audio also allows users to apply a globally-configured listener-centric reverb.

The Steam Audio plugin for Unreal Engine 4 also features plenty of other features, such as new actors and components that handle tagging acoustically meaningful geometry, specifying acoustic materials, and creating acoustic probes for baking sound propagation data.

The Steam Audio plugin for Unreal Engine 4 beta is now out. You can go here to learn more about it.